Jesus birth was a supernatural. Mary conceived Jesus in her womb by the Holy spirit. This is an important truth in the bible that is beyond what we could understand with the human mind. Even both Mary the mother of Jesus and Joseph the husband of Mary couldn’t understand; so, Joseph initially wanted to divorce Mary when he heard the news of Mary becoming pregnant.
God spoke to Mary and Joseph and informed them that this is Lord’s doing. I do not know how far Mary and Joseph could have understood the seriousness of the what angel said, but angel appeared in the dream of joseph that these things all happened as the fulfilment of the prophesies. The child formed in Mary’s womb is the Son of Living God and his name would Immanuel means “God with us” and he came to save the people from the sin. He would reign on the Throne of the David for ever and his kingdom will never end (2 Samuel 7:16).
Mary conceiving Jesus was a beginning of series of fulfilment of promises God made to the humanity. Humanity was waiting for a saviour who could forgive and deliver them from their sins, give them the hope of eternity. God’s favour was upon Mary that she was blessed to carry the very son of God in her womb. Yes, Jesus is the “Emmanuel God with us”.